Laboratory feeding device for particulate material

ABSTRACT

A vibratory feeding attachment consisting of a tube equipped with a radial connector for a threaded storage jar, a coupling element shaped for engagement by an electric or mechanical vibrator, a screen in the connector for retaining oversized particles, and an apertured partition in the tube cavity for maintaining a uniform rate of discharge of particulate material from the jar through an axially terminal opening of the tube. The attachment facilitates operation of a dispensing balance.

United States Patent [1 1 Gallati 1 LABORATORY FEEDING DEVICE FOR PARTICULATE MATERIAL [75] Inventor: Fritz Gallati, Zurich, Switzerland [73] Assignee: Mettler Instrumente AG,

Greifensee-Zurich, Switzerland [22] Filed: Aug. 15, 1973 [21] Appl. No.: 388,376

[30] Foreign Application Priority Data Aug. 24, 1972 Switzerland 12528/72 [52] U.S. Cl 222/161, 222/200, 222/564 [51] Int. Cl. B65g 65/70 [58] Field of Search 222/161, 163, 196.1, 199, 222/200, 564, 159

[56] References Cited UNITED STATES PATENTS 1,331,341 2/1920 Harnsberger 222/564 X 1,456,653

5/1923 Schling' 222/159 1' Feb. 11, 1975 2,323,864 7/1943 Weyandt 222/161 X 2,904,000 9/1959 Fisher ct al. 222/l6l X 3,029,002 4/1962 Gregoire 222/307 3,224,649 12/1965 Gunto 222/199 3,304,647 2/1967 Szekely 222/161 X Primary Examiner--Stanley H. Tollberg Assistant Examiner-John P. Shannon Attorney, Agent, or FirmHans Berman [57] ABSTRACT A vibratory feeding attachment consisting of a tube equipped with a radial connector for a threaded storage jar, a coupling element shaped for engagement by an electric or mechanical vibrator, a screen in the connector for retaining oversized particles, and an apertured partition in the tube cavity for maintaining a uniform rate of discharge of particulate material from the jar through an axially terminal opening of the tube. The attachment facilitates-operation of a dispensing balance.

9 Claims, 2 Drawing Figures LABORATORY FEEDING DEVICE FOR PARTICUIJATE MATERIAL This invention relates to vibratory feeders, and particularly to a vibratory feeding attachment suitable for feeding particulate material from a storage container to a dispensing balance.

Dispensing many small, identical weights of finely granular, powdery, or otherwise particulate, solid material is a common task in many laboratories. Direct reading balances commercially available can greatly simplify the work, but skill and care are needed for charging the proper weight of material to the balance in a quick and efficient manner. Dispensing spoons defining a fixed bulk volume when filled uniformly and known vibrating feeders are not entirely satisfactory. The dispensing spoons are not accurate enough, and time is spent for adding or removing material until the desired weight is indicated by the balance, and the available vibratory feeders need to be refilled frequently and to be cleaned when a series of weighings of one material is completed, and other material is to be dispensed.

A primary object of this invention is the provision of a vibratory feeding attachment capable of accomodating a relatively large amount of the material to be dispensed, yet inexpensive and compact enough to permit the attachment to be usedfor only one kind of material to be fed, and thus to avoid frequent refilling and clean- With these and other objects in view, as will presently become apparent, the invention provides a feeding attachment comprising a tube formed with a radial opening and an axially terminal opening. A first coupling permits a container, such as a laboratory storage jar, to be coupled to the tube in sealing engagement in a position in which the container communicates with the interior of the tube through the radial opening in the latter. A second coupling permits the-tube to be coupled with a vibrator which vibrates the tube in the direction of its axis, thereby discharging the material received from the jar through the axially terminal opening.

Other features and many of the attendant advantages of this invention will readily become apparent from the following detailed description of a preferred embodiment when considered in connection with the appended drawing in which:

FIG. 1 shows a weighing arrangement including a feeding device of the invention in an exploded side elevational view and partly in section on the tube of the feeding device; and

FIG. 2 shows the apparatus of FIG. 1 in fragmentary section on the line ll ll.

Referring now to the drawing in detail, and initially to FIG. 1, there is shown a weighing arrangement which consists of a wide-mouth glass jar 11, a feeding attachment 5 of this invention, a vibrator 19, conventional in itself, and a top-loading, single pan dispensing balance 22 carrying a beaker 23 and illustrated in a conventional manner on a reduced scale since it is not a part of the invention proper.

The feeding attachment 5 includes a straight tube 6 of transparent plastic whose cross section is uniform over its entire length, as far as not specifically described otherwise hereinbelow, and which is conveniently prepared by extrusion molding. An annular coupling adapter 7 is fixedly secured to the tube 6 in sealing engagement with the rim of a radial opening in greater than that of the tube 6, has the general shape of an internally threaded, circular or polygonal bottle cap of plastic material formed with a circular. stepped opening in its transverse face, the opening being formed in such a manner as to leave an internal, radial flange or shoulder 8 adjacent the intemal threads 9. The adapter 7 is heat-sealed or adhesively fastened to thee tube 6, and the connection is strengthened by ribs 8 fastened to outer surfaces of the tube 6 and the adapter 7, as is shown in FIG. 2.

A flat perforated plate or screen 10 is held in abutting engagement with the shoulder 8 of the adapter 7 by the wide-mouth glass jar 11 whose neck is threadedly received in the threads 9 of the adapter. Typically, its perforations have a cross section of 4 mm.

The tube 6 has a cylindrical outer, axial surface, whereas its bore has the sector shape evident from HO. 2 which is bounded in the sectional view of .FIG. 2 by two approximately straight lines converging downward toward an apex in the illustrated operative position of the device, that is, away from the adapter 7 and the corresponding radial opening in the tube 6, and an approximately circular arc connecting the diverging ends of the two straight lines. The inner walls of the tube 6 thus bound a trough of V-shaped cross section.

The interior of the tube 6 is axially divided into two compartments 12, 13 by a radial baffle or partition 14, leaving only a restricted passage 15 near the apex of the sectorshaped cross section of the tube 6. The passage 15 has a flow section which is greater than that of the individual perforations in the plate or screen 10, but only a small portion, typically one tenth or one fifteenth, of the cross section of the compartments l2, 13. The partition 14 is located close to the radial opening in the tube 6 and the adapter 7 so that the adapter couples the jar 11 to the portion of the compartment 12 axially contiguously adjacent the partition 14.

, The compartment 12 is normally sealed in an axially outward direction by a cap or cover 16, and the axially terminal opening in the tube 6 leading axially outward of the compartment 13 may be similarly sealed by a cap or cover 16' shown in phantom view in FIG. 1 since it is normally removed during operation of the feeding device 5. The caps 16, 16' may consist of somewhat resilient plastic and be retained on the tube 6 by a tight friction fit, but a threaded connection may be preferred under many conditions.

A generally rectangular coupling plate 17 is fixedly attached to the tube 6 opposite the adapter 7 in a plane through the axis of the tube, and is provided with an approximately V-shaped notch 18 in its free axial edge.

The vibrator 19, of a type basicallyknown from Re. 27,263, granted Dec. 28, l97l has'a twopart nonmagnetic housing which is approximately U-shaped. The smaller housing part 19a consitutes the free end of one leg of theU-shape, and it encloses and conceals an iron armature. An electromagnet is similarly concealed in the adjacent portion of the larger housing part 19b and may be connected to an AC outlet by means of a non-illustrated electric cord. The two housing parts 19a, 19b are connected in a parallelogram linkage by two leaf springs 24 permitting the housing part 19a to vibrate relative to the housing part 19b in the plane of FIG. 1 when the non-illustrated electromagnet is energized.

As is best seen in FIG. 2, the housing part 19a is slotted to form two jaws 20,20 sufficiently resilient to move toward each other when the knurled head of a clamping screw 21, connecting the jaws, is turned.

in operating the weighing arrangement, the nonillustrated screw cap normally closing the storage jar 11 for the material to be dispensed is removed and replaced by the feeding device 5. The housing part 19a of the vibrator 19 is slipped over the plate 17 until the screw 21 abuts against the bottom of the notch 18 whereupon the assembly may be inverted so that its components assume the respective positions seen in the drawing. When the non-illustrated electromagnet thereafter is energized, the tube 6 together with the jar 11 is reciprocated in the direction of the tube axis at the frequency of the applied current, normally 50 Hz, particles of the material stored in the jar 11 small enough to pass the perforations of the plate drop into the compartment-12 and accumulate there so that the accumulated material is driven by vibration and by static pressure, through the passage 15, migrates toward the. open end of the compartment 13, and may be dropped in a steady, fine stream into the beaker 23 on the balance 22.

The screen 10 retains particles or particle aggregations big enough to clogthe passage 15, and the-latter controls the uniform rate at which the particulate mate rial is discharged from the open end of the vibrating tube 6 under otherwise constant conditions. Depending on the size of the jarll, the feed arrangement may be supported manually during operation, as by a technicians hand gripping the jar 11, or the vibrator may be placed on a stationary-support and carry the jar 11 together with the feeding device 5. Other supporting arrangements, in which the adapter 7 constitutes the sole mechanical link between thejar 11 and the tube 6, will readily suggest themselves according to dimensions of theapparatus and specific conditions.

The progress of the dispensing operation is readily observed on the non-illustrated indicating devices of the scale 23, and feeding may be stopped by interruptingthe power supply of the electro-magnet hidden in the housing part 19b. When the vibrator 19 thereafter is disconnected from the plate 17, the remaining subassembly of feeding device 15 and jar 11 requires not significantly more space in an orderly storage array than the jar 11 alone, and the sub-assembly may be stored as such for use at a later opportunity, the contents of the jar and residual particulate material in the tube 6 being protected by the cap or cover 16. The cost of the feeding attachment 5 is low enough to make such use practical. The adapter 7 is readily transferred from an exhausted jar 11 to a full one. Non-illustrated annular inserts having internal and external coaxial threads may be inserted in the threads 9 to accomodate jars having external threads different from the threads 9.

If necessary, the feeding attachment 5 is disconnected from the jar 11 and cleaned. The screen or plate 10 is retained only by the jar l1, and drops from the disconnected coupling adapter 7 when the attachment 5 is turned about the axis of the tube 6. Removal of the caps 16, 16 permits a brush to be inserted into the compartments 12, 13 so that the feeding device 5 is capable of being cleaned quickly and simply. The transparent plastic of the tube 6 permits convenient inspection for cleanliness, but also for proper operation of the feeding attachment.

While the invention has been described with reference to a preferred embodiment, it should be understood that it is not limited to the specific materials and structural features shown and described, and that it is intended to cover all changes and modifications of the example of the invention herein chosen for the purpose of the disclosure which do not depart from the scope and spirit of the invention set forth in the appended claims.

What is claimed is: l. A feeding device comprising: a. a tube having a first axis and formed with an axially open terminal opening and a radial opening axially remote from said terminal opening;

b. first coupling means for coupling a container to 7 vibrator and for thereby vibrating said tube in the direction of said first axis, and a vibrator releasably attached to the tube by said second coupling means. 2. A device as set forth in claim 1, further comprising a container having an externally threaded neck releasably received in said adapter in threaded engagement with said internal threads, said adapter constituting the stale mechanical connection between said tube and said container.

3. A device as setforth in claim 2, further comprising a perforated screening member retained in said radial opening by abutting engagement with said neck in the direction of said second axis for preventing entry of particles from said container to said tube when said particles are greater than the perforations of said screening member.

4. A device as set forth in claim 3, further comprising a baffle in said tube axially intermediate said radial and axial openings, said baffle restricting said interior to a small passage spaced from said first axis in a direction away from said radial opening.

5. A device as set forth in claim 2, wherein said sec- 0nd coupling means include a coupling plate fixedly attached to said tube diametrically opposite said adapter in a plane through the axis of said tube.

6. A device as set forth in claim 1, further comprising a perforated screening member in said radial opening for preventing entry of particles from said container to said tube when said particles are greater than the perforations in said screening member.

7. A device as set forth in claim 6, further comprising a baffle in said tube axially intermediate said radial and axial openings, said baffle restricting said interior to a small passage spaced from said first axis in a direction away from said radial opening.

8. A device as set forth in claim 1, wherein the internal cross section of said adapter is substantially greater than the internal cross section of said tube.

9. -A device as set forth in claim 8, wherein the internal cross sectionof said tube isbounded by two substantially straight lines converging in a direction away from said radial opening and uniform over substantially the entire axial length of said tube. 

1. A feeding device comprising: a. a tube having a first axis and formed with an axially open terminal opening and a radial opening axially remote from said terminal opening; b. first coupling means for coupling a container to said tube in sealing engagement in a position in which said container communicates with the interior of said tube through said radial opening,
 1. said first coupling means including an annular adapter having a second axis transverse to said first axis and formed with internal threads about said second axis,
 2. said adapter being sealingly secured to said tube, and said second axis passing through said radial opening; c. second coupling means for coupling said tube to a vibrator and for thereby vibrating said tube in the direction of said first axis, and a vibrator releasably attached to the tube by said second coupling means.
 2. said adapter being sealingly secured to said tube, and said second axis passing through said radial opening; c. second coupling means for coupling said tube to a vibrator and for thereby vibrating said tube in the direction of said first axis, and a vibrator releasably attached to the tube by said second coupling means.
 2. A device as set forth in claim 1, further comprising a container having an externally threaded neck releasably received in said adapter in threaded engagement with said internal threads, said adapter constituting the sole mechanical connection between said tube and said container.
 3. A device as set forth in claim 2, further comprising a perforated screening member retained in said radial opening by abutting engagement with said neck in the direction of said second axis for preventing entry of particles from said container to said tube when said particles are greater than the perforations of said screening member.
 4. A device as set forth in claim 3, further comprising a baffle in said tube axially intermediate said radial and axial openings, said baffle restricting said interior to a small passage spaced from said first axis in a direction away from said radial opening.
 5. A device as set forth in claim 2, wherein said second coupling means include a coupling plate fixedly attached to said tube diametrically opposite said adapter in a plane through the axis of said tube.
 6. A device as set forth in claim 1, further comprising a perforated screening member in said radial opening for preventing entry of particles from said container to said tube when said particles are greater than the perforations in said screening member.
 7. A device as set forth in claim 6, further comprising a baffle in said tube axially intermediate said radial and axial openings, said baffle restricting said interior to a small passage spaced from said first axis in a direction away from said radial opening.
 8. A device as set forth in claim 1, wherein the internal cross section of said adapter is substantially greater than the internal cross section of said tube.
 9. A device as set forth in claim 8, wherein the internal cross section of said tube is bounded by two substantially straight lines converging in a direction away from said radial opening and uniform over substantially the entire axial length of said tube. 